Correlation of serum parathormone level with biochemical parameters in chronic renal failure.

A prospective study was carried out to assay the level of serum intact parathormone and its correlation with biochemical parameters in patients with chronic renal failure (CRF). The study included 64 children (44 with CRF, and 20 age and sex matched controls). Serum intact parathormone (iPTH), serum creatinine, urea, calcium, inorganic phosphate and alkaline phosphatase were estimated. Creatinine clearance (Ccr) was estimated by Schwartz formula. Patients with CRF were divided into four groups based on their Ccr (mild CRF with mean Ccr 59.17 +/- 1:18.53 mL/min/1.73 m2 (n = 6) moderate CRF with mean Ccr 34.98 +/- 7.75 mL/min/1.73 m2 (n = 7); severe CRF with mean Ccr 17.71 +/- 5.40 mL/min/1.73 m2 (n = 15); and end-stage renal disease with mean Ccr 6.46 +/- 1.71 mL/min/1.73 m2 (n = 16). Mean serum iPTH levels were 93.00 +/- 46.62 pg/mL in CRF and 16.52 +/- 9.35 pg/mL in controls. Groupwise mean serum (iPTH) levels were 48.50 +/- 4.76, 67.29 +/- 7.91, 82.42 +/- 9.67 and 130.66 +/- 58.74 pg/mL in mild, moderate, severe CRF and endstage renal failure respectively. Mean serum iPTH level of CRF (93.00 +/- 46.42 pg/mL) negatively correlated with mean Ccr (22.02 +/- 18.53 mL/min/l.73 m2) (P < 0.001) and mean serum calcium (7.30 +/- 1.02 mg/dL) (P < 0.001) and positively correlated with mean inorganic phosphate (5.76 +/- 1.1 mg/dL) (P < 0.05) and mean alkaline phosphatase (355.14 +/- 185.53 UL) (P < 0.001). We conclude that increased iPTH level occur even early in the course of CRF and progressive hypocalcemia and hyperphosphatemia are the initiating factors for the development of hyperparathyroidism.